Machines such as medium duty and heavy duty on-highway trucks, hydraulic excavators, wheel loaders, off-highway trucks, other heavy construction and mining machines, automobiles, motorcycles, and other equipment, are used to perform many tasks. To effectively perform these tasks, many of these machines require a power source, such as an internal combustion engine. Internal combustion engines often include an intake manifold, a housing, such as an engine block, and one or more working members, such as pistons. Typically, each working member is movably supported within the housing of the engine and separates a combustion chamber from a non-combustion chamber of the housing, such as a crankcase. Such engines combust air from the intake manifold, and fuel, in the combustion chamber to produce power by driving the working member.
High pressure in the intake manifold and combustion chamber may drive combustion gases and other intake gases through spaces between the housing and the working member, into the non-combustion chamber. These gases (sometimes referred to as “blow-by gases”) may increase the pressure in the non-combustion chamber to a high level. The pressure in the non-combustion chamber may be relieved using a ventilation system, which results in predictable pressure changes in the non-combustion chamber as a result of intake pressure changes. However, in certain situations, the pressure may be relieved through cracks, corroded portions, faulty valves, or other faults in the non-combustion chamber and/or ventilation system, thereby leaking into the atmosphere.
Such leakage may result in unexpected pressure changes in the crankcase, and is typically undesired as it may decrease efficiency of the engine. Furthermore, venting combustion gases from the non-combustion chamber directly to the atmosphere has negative environmental consequences, and may cause a machine to fail to achieve required emissions standards.
One known method for determining a fault in a ventilation system of an engine is disclosed in U.S. Patent Application Publication No. 2005/0022795 A1, to Beyer et al. (“the '795 application”). The '795 application describes a method for determining a fault in the ventilation system of an engine by monitoring an intake manifold pressure for the engine, a crankcase ventilation pressure, and an ambient air pressure. The method determines a fault by determining at least one pressure differential between one of an intake manifold pressure and a pressure in the ventilation duct, and an ambient pressure and the pressure in the ventilation duct. However, the '795 application does not account for a time-based analysis of fluid pressure in the engine, and additionally fails to analyze the changes in crankcase pressure due to changes in intake pressure.
The engine of the present disclosure overcomes one or more of the problems discussed above, and/or other problems in existing technology.